Bearing and seal



July 29, 1941. MURPHY I 2,251,020

' BEARING AND SEAL Filed Dec. 30, 1938 2 Sheets-Sheet 1 INVENTOR gam/W23 aw v July 29, 1941. D. MURPHY BEARING ANDSEAL Filed D96. :so,1938 2 Sheets-Sheet 2 R o T N E V m Patented July 29, 1941 UNITED STATEs PATENT OFF-[cs V Claims. My invention relates to pumpbearings.Particularly to bearings for the impellers of centrifugal pumps. Theinvention consists in im-- provements and refinements in bearingconstruction and in organization of the bearing in a centrifugal pump. 7r

Referring to the accompanying drawings, Fig I is a view, partly in sideelevation and partly in, vertical section, of a centrifugal pumpincluding a bearing of the invention; Fig. 11 is a fragmentary view,showing portions of the bearing structure, partly in axial section andpartly in side elevation, on larger scale; Fig. 111 is a view in frontelevation and on still larger scale of a particularly effective sealingdevice included in the bearing structure; and Fig. IV isa view in medialcross section of such sealing device, the device being showninposition'for assembly in the struc: ture, with portions of thestructure illustrated fragmentarily The exemplary pump consists in abody includingtwo sections l and 2, bolted together and ization of pumpbearings, and to a consideration of I the embodiment of the inventionherein illustrated. v

At the outset it will be understood that; the shaft 5 and impeller B,collectively considered, comprise a member or unit that in servicerotates relatively to'the stationary body of the pump. The bearing isborne by such stationary body for the support of the rotary unit 5, 8.The bearing structure includes a tubular support-3 that provides (orcarries) abearing for the impeller 8. At its right hand end the tubularsupport includes a radially extending portion 311 that-is rigidlysecured to the body -of the pump. The support 3 is in effect a hollowcantilever beam that is adapted to carry a bearing at its distal end. iMore specifically, the wall forming an involute pump chamber 4 of usualsort. A vaned impeller 8 is mounted for rotation in such chamber, and ashaft 5, profecting at in from th pummstructure, is geared to a suitablemotor for driving the impeller. The pump body includes aninlet passageI, extending from above the pump chamber 4 downward. and openingcentrally of the impeller vanes through the side wall of such chamber,the side wall including in this case a centrally perforate wearing disk2| that cooperates with such vanes.

An outlet passage 8 opens tangentially through the peripheral wall ofthe pump chamber and extends upward to a receiver-chamber 31 included inthe delivery line 310 leading from the pump, In service the rapidlyrotating impeller draws liquid inward through passage I into the spacesbetween the vanes of the impeller, whence centrifugal forceimpelstheliquid radially outward into the outlet passage 8.

The liquid entering the pump is drawn upward through a duct 3| from thesupply, and in the line of flow between-the duct 3i and passage 4 I acheck-valve is included. The check-valve is arranged in a chamber 33,located above the pump chamber. Further reference to the constructionand operation of the pump is unnecessary'to an understanding of thisinvention, but to the extent that such matters of detail may be-ofinterest I refer the reader to United States Letters Patent No.2,179,858, granted to me November 14, 1939. As already mentioned, thepresent invention concerns the structure and organs against a collar 50on the'shaft 5 and an inter of the inlet passage I of the pump includesan opening la. opposite to and in axial alignment with the inlet Zia tothe pump chamber 4, and

the pump body includes a cylindrical housing portion la extendingoutward from and in axial alignment with such opening la. The tubularsupport extends through opening la, and the radial portion 3d at itsproximal end is, by means of a sleeve 30 and screws 30a, clamped'rigidlyagainst the wall portion of the pump that surrounds said opening fla.One or more'gaskets 2o insure a sealed union of the parts, with theconsequence that liquid is prevented from leak 'ing' fromthe inletpassage '8 of the pump into the housing la. Within the housing la, con-'venientlywithin the sleeve 3D, a bearing is provided for. the shaft 5,and it is manifest from what has been said that such bearing ishydraulically sealed from theliquid flowing through the passage I. Thebearing may consist in a conventional ball-bearing 25, held in place,

nal shoulder 84 on the, sleeve 30, by means of a keeper 35. The keeperconsists in a flanged block snugly fitting the bore of the sleeve, and

secured in assembly by means of screws 36. The body of the keeper isrecessed, and providedwith a packing 38 of felt or the like that servesto prevent the escape of lubricant which in service is supplied to achamber A within the sleeve.

The shaft 5 extends from the bearing 25 through the tubular support 3,and impeller iis'secured to the inward projecting end of the shaft, asshown in Fig. II. The impeller is provided with a hub 60, which islarger than the hubs usually provided on pump impellers, and

such hub is internally recessedto receive a bearing 8 and a pair ofsealing devices It and 15.

1 shall now mm- The integration of the shaft with the impeller isefl'ected by means of a member 6|, which is screwed on and locked to theend of the shaft, and it will be perceived that member 6| is securedover the open end of the hub, say by means of screws 82.

ing la is completely sealed from the liquid being pumped, and in thecase oi the bearing within the hub 01' the impeller the only possibleavenue through which liquid may enter is the clearance between thetubular support 3 and the periphery of the aperture 611. The sealingdevice i5 closes such avenue.

While various forms of sealing devices may be used, it is to beunderstood that the device i 5 is particularly efl'ective. This deviceconsists in a resilient diaphragm il, a centrally perforated, circulardiaphragm of sheet metal, which is mounted on and arranged radially oithe tubular support 3. The diaphragm carries a sealing ring l2 at itsouter periphery; the sealing ring is held in snug contact with the wallportion of the ima pellet that surrounds aperture 6b; and the innerperiphery of the diaphragm is secured and sealed upon the body of thecylindrical support 3. More specifically, the sealing ring i2 is formedin two sections Ho and l2b, as shown in Fig. IV; the

two ring sections are closed and secured upon the periphery of thediaphragm ii, by means of screws i3, and a gasket it; of rubber isinterposed between the ring sections, as shown, to provide aliquid-tight union of the ring with the outer periphery of thediaphragm. The inner peripheral edge of the diaphragm is secured andsealed between the companion edges of two sleeves ii and it that aremounted with snug fit on the tubular support 3. The right-hand edge ofsleeve i'i abuts against a rigid collar to on the support 3; in makingthe assembly the sleeve ii is mounted in the position in which it isillustrated on the cylindrical support 3, and

then the sealing device l5 and the sleeve l8 are slipped over the end'of cylindrical support, and moved into position, as indicated by thearrows in Fig. IV. As presently will appear, the sleeves are tightlysecured on the support 3, with the inner edge of the diaphragm iiclamped and sealed between the companion edges oi the sieves. With thediaphragm so assembled on the stationary support 3, the sealing ring I2is urged and maintained in contact, as at S, with that body portion ofthe rotary impeller which bounds the opening 6b, through which thesupport and shaft assembly 3, 5 extends. Thus, it will be understoodthat the only avenue through which liquid may leak from the'pump intothe bearing 9 is closed.

As shown in Fig. II, springs l0 may be arranged to maintain the sealingring i 2 in the desired contact with the body of the impeller.Additionally, the inherent resilience of the diaphragm cooperates tothis end-indeed, in many cases the resilience of the diaphragm willprove adequate without the springs Hi. In order to augment the efiect ofthe resilience oi the diaphragm, I chamfer or bevel the companion edgesof the sleeves I! and i8, and the direction of 1 bevel, as may beperceived in Fig. IV, is such that (when the two sleeves are tightlyclamped upon the inner edge of the diaphragm) the body of the diaphragmis flexed, in such manner that the sealing ring I! is more stronglyurged and held in snug contact with the wall portion 6a of theimpeller."

Other advantages attend the use of my diaphragmatic sealing device, andnotable among such advantages is the feature of self-alignment. Thoseskilled in the art will readily understand this matter ofself-alignment, and I need merely remark that the flexible diaphragm Hfunctions in such manner that the sealing ring l2 always remains in snugcontact with the body of the rotating impeller.

When the pump is in operation the suction produced by the rotatingimpeller will act through the clearance 6b upon the diaphragm H, and,under the influence of this suction on the dia phragm, the sealing ringI2 is held all the more snugly against the body portion 6a of theimpeller. In fact, so long as the pump is in operation, there is notendency for liquid to leak from the pump chamber 4 into the bearingchamber B within the impeller hub, rather the tendency is for therotating impeller to suck lubricant from the bearing chamber into thepump chamber. It is only while the pump is at rest that the sealingdevice i5 serves to prevent the infiltration of liquid from the pumpchamber 4 to the bearing chamber B. And it is important to note that thepressure head of the liquid, normally tending (when the pump is at rest)to destroy the seal provided by the device I5, is neutralized. That is,the pressure of the liquid standing in the discharge line and pumpchamber is communicated through theclearance 6b to the right-hand face(Fig. IV) of the diaphragm, and such pressure on the diaphragm tends toshift the ring l2 from sealing contact with the wall portion 6a of theimpeller. However, the pressure of the liquid efiective on theright-hand face of the diaphragm is also effective on the left-hand faceof ring section i2b. Manifestly, the liquid pressure tending to unseatthe ring l2b from wall portion 6a is in large measure neutralized, withthe result that the device l5 provides an eifective seal against theinfiltration of liquid to housing 60.

In the usual pump, the sealing device IE will prove adequate, but Icontemplate that in some cases several sealing devices will be used. Asan example I show in Fig. 11 a second sealing device I. The innerperipheral edge of the diaphragm of this second sealing device isclamped between sleeves 22 and 24, the counterparts of sleeves i1 andI8, respectively. And the ring I20 carried at the outer edge of thediaphragm bears, with liquid-sealing contact, upon the inner surface ofa cup-shaped bearing retainer 26 provided in the impeller hub 60.

The end of the cylindrical support 3 is threaded, and the assembly ofthe bearing 9 and sealing devices I, I5 upon such support is secured bymeans of a single nut 21. That is to say, the nut 21 is tightenedagainst the inner ring of ball-bearing 9, and under the thrust of thenut such ring is pressed inward on the tubular support 3. Abutting uponthe left-hand edge of sleeve 24, the ring 9 0 under nut pressure forcessleeves 24, 22, l8, i! into tight edge-toedge assembly, with the inneredges of the diaphragms of scaling devices l4 and I5 clamped and sealedin the manner already described. Manifestly, the structure is easilyassembled.

bearing for a pump impeller as close to the impeller as possible, inorder to minimize the objectionable tendency of the rotating impeller'tovibrate and of the driveshaft to whip. In my structure the bearing 9 isarranged within the body of the impeller itself; the shaft 5, extendingthrough or across the lower. or innerend of the inlet passage 1, isprovided with bear-y ings on each side of such inlet passage, andbyvirtue of these and other refinements the.objections noted areeffectively eliminated.

It will be perceived that the rotary shaft 5 is at-all points in itsextent free from frictional contact with the stationary parts of thepump structure, and I call particular attention to the clearance C whichis provided between the shaft and the cylindrical wall of the support 3.There is no wear upon the shaft. Not only are the bearings 9 and 25enclosed and sealed from the liquid being pumped, but the shaft 5 itselfis enclosed. The liquid being pumped is excluded from the shaft, and afilm of lubricant may be maintained on the surface of the shaft, toinhibit rustingand corrosion. Such features as these,

while valuable in any machine, are particularly valuable in heavy-dutypumps, pumps that work upon liquid including particulate solids,such asthe "slip used in potteries.

In all pumps of the sort described herein, it is desirable to providefor the axial adjustment of theimpeller, so that the free side edges ofthe impeller vanes may be brought to proper position with respect to theside wall 2| of the pumpchamber. Such adjustment of the impeller may beobtained in a variety of ways, and inthis case I effect it by varyingthe thickness of the gasket 20. That is, the gasket is made up of aplurality of thin gasket rings, and, by

, the adding or removing of such rings, the effective thickness of thegasket maybe increased or decreased. The adjustment of the axialposition of not only the impeller, but of the enand hearing aslubricant.The clearance C between shaft 5 and the wall of tubular support 3provides communication between the well A and the bearing 9 within thehub of the impeller, and thus it is that lubricant introduced to well Ais delivered to both of the bearings 9 and 25. The structure provides asingle lubricating system for the bearings of the pump, and the devicesIt and 38 close and seal the system against the escape of lubricant.

The sealing devices l4 and I5 are also lubricated, and graphite hasproved to be a good lubricant. Advantageously, the rings I2, I28 of thesealing devices are provided with pockperiods of time all thelubrication that is necsar The, chamber B may be charged with a store oflubricant when the pump is assembled, but such lubricant will be alighter,- more fluid type than the graphitic-base lubricant used inpockets 32. Of course, the wall of the hub '60 may be provided with aninlet (not shown) for charging the chamber B, but itis deemed needlessto prolong this specification with such matters of detail.

Within the-terms and intent of the appended claims various modificationsof the structure described lie within the fleldof my invention.

I claim as my invention: 3

l. A hearing structure for the impeller and shaft of a rotary pumpincluding within its body an impeller chamber and an'inlet passagearranged side by side and a port establishing com-' municationtherebetween, said pump being adapted to pump heavy liquid includingabrasive particles, said bearing structure .including two bearingsarranged outward from and on opposite sides of said chamber and passage,one of such bearings being housed within the impeller body, a tubularsupport secured at one end to the pump body and/extending from theregion of its attachment to such body transversely through both saidinlet passage and said impeller chamber, and

at its distal end extending into said impeller body and providingsupport for the bearing therein, said shaft extending through saidtubular support and secured adjacent to the distal end thereof to saidimpeller, and means cooperating with such tubular support and theimpeller body for sealing the bearing on the distal end of said tubularsupport within the impeller body.

2. A bearing structure for the impeller and shaft of a rotary pump thatincludes an impelelr chamber, inlet and outlet passages, a port in onesidewall of said chamber establishing communication between the chamberand said inlet passage, said impeller carrying vanes adapted tocooperate with saidrperforate side wall of the pump chamber when thepump is in operation;

' said bearing structure including a bearing orets '32 (Figs. III andIV) that open through ganized within the impeller body, and a rigidtubular support arranged to extend from said inlet passage and throughsaid port in the side wall of the impeller chamber of the pump, with thedistal end of such support'located within the impeller body andaffording support for said bearing, and means providing for the axialadjustment of such tubular support, withthe effect that the impeller andbearing assembly may be adjusted and the most effective relation of theimpeller vanes with respect to said perforate side wall of the impellerchamber established and maintained.

3. A pump impeller structure comprising an impeller body including abody portion that extends radially of the axis of the impeller'andincludes a central perforation, said radially extending body portioncarryingon one side an impeller vane and carrying on opposite side ahollow imperforate-walled hub; a tubular, cantilever-like supportextending through the per-- foration in such radially extending bodyportion ofthe impeller, a bearing borne by the distal-end of-suchsupport within said hub, a drive-shaft extending through said tubularsupport and integrated to the impeller hub, and a perforate flexiblediaphragm secured and sealed at the rim of its perforation to saidtubular support and at its outer peripheral edge encompassing theperforati'on in such impeller body portion and engaging such bodyportion of the impeller in an engagement preventative of liquid flowinward of the hollow hub and toward the bearing within.

4. A pump impeller including a bearing chamber whose walls, otherwiseimperforate to liquid, include a port; a tubular cantilever-support extending through such port and carrying at its distal end a bearingwithin such chamber; and means for sealing the hearing within theimpeller body, said means comprising a perforate flexible diaphragmsecured and sealed at the rim of its perforation to said tubular supportand at its outer rim encompassing the periphery of said port and bearingoutward of the bearing chamber upon the port-encompassing body portionof the impeller, with the effect that the suction produced by theimpeller within a pump in operation is eiiective upon said diaphragm toassist in holding the outer rim of the diaphragm in sealing contact withsaid port-encompassing body portion of the impeller.

ber whose walls, otherwise imperforate to liquid, include a port; atubular cantilever-like support extending through such port and carryingat its distal end a hearing within such chamber; and means comprising aperforate flexible diaphragm secured and sealed at the rim of itsperforation to said tubular. support and at its outer rim encompassingthe periphery of said port and hearing outwardof the bearing chamberupon the port-encompassing body portion of the impeller, with the effectthat the suction produced by the impeller within a pump in operation iseflective upon said diaphragm to assist in holding the outer rim of thediaphragm in liquid-excluding contact with said port-encompassing bodyportion of the impeller, and a second sealing device housed within thebearing chamber in said impeller and arranged between said bearing andsaid diaphragm in lubricant-confining contact with a rotary portion ofthe impeller structure. DANIEL MURPHY.

5. A pump impeller including a bearing cham-

